1. Field
Example embodiments relate to an image sensor, and in particular, to a complementary metal-oxide semiconductor (CMOS) image sensor.
2. Description of the Related Art
An image sensor is a device that converts optical images into electrical signals. With increased development of the computer and communications industries, there is an increased demand for high performance image sensors in a variety of applications, e.g., digital cameras, camcorders, personal communication systems, gaming machines, security cameras, micro-cameras for medical applications, and/or robots.
The image sensors may be generally classified into charge coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) image sensors. The CMOS image sensors are operated using a simple operation method and are configured to have signal processing circuits integrated on a single chip, and thus, it is possible to realize products including scaled CMOS image sensors. In addition, CMOS image sensors may operate with relatively low consumption power, and thus, they are applicable to a product with low battery capacity (e.g., portable electronic devices).
As the electronic industry advances, there is an increasing demand for an image sensor with a high density and a reduced pixel size, and many researches are being conducted to develop such an image sensor.